2018-02-18T01:03:32ZAssociation Studies and Direct DNA Sequencing Implicate Genetic Susceptibility Loci in the Etiology of Nonsyndromic Orofacial Clefts in Sub-Saharan African Populationshttp://hdl.handle.net/123456789/11070
Title: Association Studies and Direct DNA Sequencing Implicate Genetic Susceptibility Loci in the Etiology of Nonsyndromic Orofacial Clefts in Sub-Saharan African Populations
Authors: Gowans, L.J.J.; Adeyemo, W.L.; Eshete, M.; Mossey, P. A.; Busch, T.; Aregbesola, B.; Donkor, P.; Arthur, F.K.N.; Bello, S. A.; Martinez, A.; Li, M.; Agbenorku, P.; Augustine-Akpan, E.A.; Deressa, W.; Twumasi, Peter; Olutayo, J.; Deribew, M.; Obiri-Yeboah, S.; Oseni, G.O.; Olaitan, P.B.; Abdur-Rahman, L.; Abate, F.; Hailu, T.; Gravem, P.; Ogunlewe, M.O.; Buxó, C.J.; Marazita, M.L.; Adeyemo, A. A.; Murray, J. C.; Butali, A.
Abstract: Orofacial clefts (OFCs) are congenital dysmorphologies of the human face and oral cavity, with a global incidence of 1 per 700 live births.
These anomalies exhibit a multifactorial pattern of inheritance, with genetic and environmental factors both playing crucial roles. Many
loci have been implicated in the etiology of nonsyndromic cleft lip with or without cleft palate (NSCL/P) in populations of Asian and
European ancestries, through genome-wide association studies and candidate gene studies. However, few populations of African descent
have been studied to date. Here, the authors show evidence of an association of some loci with NSCL/P and nonsyndromic cleft palate
only (NSCPO) in cohorts from Africa (Ghana, Ethiopia, and Nigeria). The authors genotyped 48 single-nucleotide polymorphisms that
were selected from previous genome-wide association studies and candidate gene studies. These markers were successfully genotyped
on 701 NSCL/P and 163 NSCPO cases, 1,070 unaffected relatives, and 1,078 unrelated controls. The authors also directly sequenced 7
genes in 184 nonsyndromic OFC (NSOFC) cases and 96 controls from Ghana. Population-specific associations were observed in the casecontrol
analyses of the subpopulations, with West African subpopulations (Ghana and Nigeria) showing a similar pattern of associations.
In meta-analyses of the case-control cohort, PAX7 (rs742071, P = 5.10 × 10-3), 8q24 (rs987525, P = 1.22 × 10-3), and VAX1 (rs7078160, P
= 0.04) were nominally associated with NSCL/P, and MSX1 (rs115200552, P = 0.01), TULP4 (rs651333, P = 0.04), CRISPLD2 (rs4783099,
P = 0.02), and NOG1 (rs17760296, P = 0.04) were nominally associated with NSCPO. Moreover, 7 loci exhibited evidence of threshold
overtransmission in NSOFC cases through the transmission disequilibrium test and through analyses of the family-based association for
disease traits. Through DNA sequencing, the authors also identified 2 novel, rare, potentially pathogenic variants (p.Asn323Asp and
p.Lys426IlefsTer6) in ARHGAP29. In conclusion, the authors have shown evidence for the association of many loci with NSCL/P and
NSCPO. To the best of this knowledge, this study is the first to demonstrate any of these association signals in any African population.
Description: An article published by Journal of Dental Research 2016, Vol. 95(11) 1245– 1256;DOI: 10.1177/00220345166570032016-01-01T00:00:00ZPrevalence of papC and usp Virulence Factors in Uropathogenic Escherichia coli Causing Asymptomatic Urinary Tract Infections in Adolescentshttp://hdl.handle.net/123456789/11069
Title: Prevalence of papC and usp Virulence Factors in Uropathogenic Escherichia coli Causing Asymptomatic Urinary Tract Infections in Adolescents
Authors: Darko, Samuel Nkansah; Nsiah, Kwabena; Twumasi, Peter
Abstract: Aims: To determine the prevalence of two virulence genes associated with uropathogenic
Escherichia coli; papC gene of the P fimbriae for adherence to uro-epithelial cells and usp
(uropathogen-specific protein) gene, a Vibrio cholerae toxin gene homologue.
Study Design: Cross sectional.
Place and Duration of Study: Department of Biochemistry and Biotechnology and the
Clinical Analysis Laboratory, Kwame Nkrumah University of Science and Technology,
Kumasi, between October 2011 and February 2012.
Methodology: Escherichia coli isolates (n= 149) from an adolescent population of ages 13-
18 years (from a total sampled population of 85 males and 64 females) were screened for
papC and usp, using specific primers for the two genes in polymerase chain reactions.
Results: The usp gene was the most prevalent (72.48%), followed by papC (51.00%) and
papC+usp (24.16%). Significant difference (P = .002) was observed between papC and usp
and also papC and papC+usp (P < .0001). usp Gene prevalence was also significantly
different from that of papC+usp (P < .0001).Conclusion: This study suggests that a higher proportion of strains of uropathogenic
Escherichia coli implicated in UTI in the studied population possess the usp gene whose
protein product potentially serves to reduce competing microbes in the urinary tract.
Description: An article published by British Microbiology Research Journal
3(3): 423-430, 20132013-01-01T00:00:00ZUse of simple sequence repeat (SSR) markers to establish genetic relationships among cassava cultivars released by different research groups in Ghanaianhttp://hdl.handle.net/123456789/11068
Title: Use of simple sequence repeat (SSR) markers to establish genetic relationships among cassava cultivars released by different research groups in Ghanaian
Authors: Quain, Marian Dorcas; Acquah, Eric WArren; Twumasi, Peter; Parkes, Elizabeth Y.
Abstract: Cassava (Manihot Esculenta) is an important staple crop widely cultivated in Ghana. The crop also has diverse industrial applications like starch, beer and alcohol productions. Knowledge about the state of the Ghanaian genetic diversity and population structure is paramount in breeding programmes aimed at cultivar improvements..............
Description: An article published by International Journal of Genetics and Molecular Biology;Vol.6(3), pp. 29-36, October, 20142014-10-01T00:00:00ZEstablishing in vitro Zinnia elegans cell suspension culture with high tracheary element differentiationhttp://hdl.handle.net/123456789/11067
Title: Establishing in vitro Zinnia elegans cell suspension culture with high tracheary element differentiation
Authors: Twumasi, Peter; Schel, Jan H.N.; Ieperen, Wim van; Woltering, Ernst; Emons, Anne Mie C.
Abstract: The Zinnia elegans mesophyll cell culture is a useful system for xylogenesis studies. The system is associated with highly synchronous
tracheary element (TE) differentiation, making it more suitable for molecular studies requiring larger amounts of molecular isolates, such as
mRNA and proteins and for studying cellulose synthesis. There is, however, the problem of non-uniformity and significant variations in the
yields of TEs (%TE). One possible cause for this variability in the %TE could be the lack of a standardized experimental protocol in various
research laboratories for establishing the Zinnia culture. Mesophyll cells isolated from the first true leaves of Z. elegans var Envy seedlings of
approximately 14 days old were cultured in vitro and differentiated into TEs. The xylogenic culture medium was supplied with 1 mg/l each of
benzylaminopurine (BA) and a-naphthalene acetic acid (NAA). Application of this improved culture method resulted in stable and reproducible
amounts of TE as high as 76% in the Zinnia culture. The increase was mainly due to conditioning of the mesophyll cell culture and adjustments
of the phytohormonal balance in the cultures. Also, certain biochemical and cytological methods have been shown to reliably monitor progress
of TE differentiation. We conclude that, with the adoption of current improvement in the xylogenic Z. elegans culture, higher amounts of
tracheary elements can be produced. This successful outcome raises the potential of the Zinnia system as a suitable model for cellulose and
xylogenesis research
Description: An article published by Cell Biology International 33 (2009) 524-5332009-01-01T00:00:00Z